Base for incandescent lamps.



No. 760,065. PATENTED MAY 17, 1904. H. GILMORE. BASE FOR INGANDESGENT LAMPS.

APPLICATION FILED NOV. 22, 1901.

H0 MODEL.

UNITED STATES Patented May 17, 1904.

HOWARD GILMORE, OF BOSTON, MASSACHUSETTS.

BASE FOR INCANDESCENT LAMPS- SPECIFIGATIQN forming part of Letters Patent No. 760,065, dated May 17, 1904;.-

Application filed November 22, 1901. $eria11lo. 83,256. (No model.)

To all whom it may concern:

Be it known that I, HOWARD GILMORE, of Boston, in the county of Suffolk and State of Massachusetts, have invented a new and useful Base for Incandescent Lamps; and I hereby declare the following to be a clear, full, and exact description of the same, reference being had to the accompanying drawings, forming part of this specification.

All the common lamp-bases consist of at least four parts, a button or bodypart, which is an insulator, two contacts parts, and a cup part. Usually, however, the cup part is formed by extending one of the other parts, so as to form a cup, so that often the base has only three separate distinct pieces. The lamp-bulb is usually attached to the base by placing the neck of the lamp into the cup part and filling up the space with plaster, the two contact parts being connected, respectively, to the two terminals of the filament. The body part of base serves to hold the other parts together. One ormore parts of the base are also so shaped that they will fit into corresponding parts in a holder or receptacle intended to support the lamp, so that the base when attached to a lam p serves two functionsfirst, as substantial terminals for the ends of the filaments; second,as asupport for the lamp as a whole.

In the drawings, Figure 1 illustratesalamp in connection with a lamp-base, which embodies my invention. Fig. 2 illustrates a modification of the base. Fig. 3 shows the base of Fig. 1, but not fully completed.

In prior lamp-bases for use with hermetically-sealed bulbs-that is, in which the neck of the bulb is cemented in one end of a metal tube and the insulating-body part connected with the opposite end of that tube-the outer end of the tube has heretofore been spun directly upon the insulating-body part; and the object of my invention is to remedy certain practical objections to those forms of lampbases, principally undue length of the tubular base when the body part is of a substance, such as porcelain or glass, that will not absorb moisture.

By my invention I can cheaply obtain the minimum as to length and at the same time use a substance that willnot absorb moisture, such as porcelain or glass. Figs. 1 and 2 show sections of forms of my invention. Fig. 1 shows the form I prefer, as it is the cheapest to construct and is nearly waterproof.

In all the figures, A and D are the contact parts, B is the body part, and O is the cup or metal tube. Contact D serves to hold the base in its socket or receptacle. None of these parts do I claim broadly as my invention, for my invention is the combination of the usual screw-shell, open at one end to receive the sealed neck of the bulb, with a holder for the body part wholly inclosed by the screw-shell, so that the body part does not project from the screw-shell, as heretofore, and a frictional contact carried by the body part and adapted to make electrical contact with one of the terminals of the lamp.

The difference between my way and the common way is that I use an inner holder F for the body part, which inner holder has a projection to enter a recess in the body part or a recess to receive the edge of the body part, while in the common way the holder, with its recess or projection, is the outer end of the cup or metal tube itself. It is obvious that my inner holder F can be made either as a separate'piece and attached to the cup, as in Fig. 2, or it can be one piece with the cup, as in Figs. 1 and 3, without changing the idea of my invention.

The main advantage due to the use of my inner holder F, sunk below the edge of the shell or tube O, is that the length of shell C is decreased by the fact that the holder F is so sunk, and this is an important practical feature, for it is desirable to decrease the length of this shell O as far as possible consistent with its practical use as the outer contact of the lamp, and before my invention the length of this shell O was necessarily not only suflicient for that use, but also for use as a holder for the body part B. While this is the main advantage of my invention, other advantages are the decrease in the diameter of the body part B and improvement in appearance of the base, due to the fact that the body part B is sunk into the outer end of shell 0 and sustained therein by the inner holder F.

Fig. 1 shows the best form, in my opinion, of my invention. The cup C is drawn up, as shown in Fig. 3, and any one skilled in the art will fully understand how this is done without further description. The body B is then inserted in the holder F and there secured by turning the edge f, as shown in Fig. 1.

It is evident there are many other ways of accomplishing the same result, as by first spinning my inner holder F on body B and then securing holder F with body B to the cup (I, as in Fig. 2.

I am aware that metallic stoppers for lamps are shown in British Patent No. 4,311 of 1881 and in United States Patent No. 261,263 to Seymour, dated July 18, 1882, and I am also aware of the usual lamp-base shown in United States Patent No. 651,695 to Bryant, dated June 12, 1901, and disclaim all that is shown in those patents.

Having thus described my invention, I claim-- In an incandescent-lamp base, comprising a screw-shell open at one end to receive the neck of the bulb, the combination of an insulatingbody at the other end of the shell; a central frictional contact, electrically connected with one of the leading-in wires and thereby with one terminal of the filament; and an inner holder concentric with and inclosed within the screw-shell to carry the insulating-body and central contact, all substantially as, and for the purposes, specified.

HOl/VARD GILMORE.

Witnesses:

J. E. MAYNADIER, JOHN R. Snow. 

